Spreading and rapid solidification behavior of millimeter-scale molten drops of 8 wt.% yttria-stabilized zirconia (YSZ) has been experimentally studied utilizing a novel splittable aerodynamic levitator (ADL). The focus was especially on the effect of initial undercooling on the splat formation. An YSZ sphere approximately 2.3 mm in diameter was levitated in a splittable ADL nozzle and melted by a carbon dioxide laser. The molten drop was dropped by splitting the ADL nozzle and impacted on a substrate 15 cm below at a speed of 1.7 m/s. The spreading and solidification behavior of the impacting drop was observed with a high-speed digital video camera. The undercooling of YSZ drops reached to more than 500 K at a containerless state, and the solidification rate was on the order of 1 m/s at this state. When drops were dropped at superheated states, the drop solidified after flattening completed. Meanwhile, when impacted at large undercooling, the drop spreading was suppressed by the solidification. Drastic difference was observed when a drop was impacted on a substrate covered with acetone liquid. The drop was splashing, recoiling, and rebounding despite fact that splashing would not occur at this impact condition.
展开▼
机译：毫米级的8重量％氧化钇稳定的氧化锆（YSZ）的熔融液滴的扩散和快速凝固行为已通过新型可分裂的空气动力学悬浮剂（ADL）进行了实验研究。重点尤其放在初始过冷对飞溅形成的影响上。将直径约2.3毫米的YSZ球悬浮在可拆分的ADL喷嘴中，并用二氧化碳激光熔化。通过分开ADL喷嘴滴下熔滴，并以1.7 m / s的速度撞击在15 cm以下的基材上。用高速数字摄像机观察了冲击滴的扩散和固化行为。在无容器状态下，YSZ液滴的过冷度达到500 K以上，在此状态下，固化速度约为1 m / s。当液滴在过热状态下滴下时，在压平完成后液滴固化。同时，当受到较大的过冷影响时，液滴的凝固被凝固抑制。当液滴撞击在覆盖有丙酮液体的基材上时，观察到巨大的差异。尽管实际上在这种冲击条件下不会发生飞溅，但液滴仍在飞溅，回弹和反弹。
展开▼
